There have been conventionally known discharge units which discharge between a discharge electrode and a counter electrode. A discharge unit is mounted on such a device as an air conditioner, an air cleaner, or the like (e.g. Japanese Unexamined Patent Publication No. 2005-100936). In the discharge unit recited in paragraphs 0095 and 0096 and FIG. 7 of Japanese Unexamined Patent Publication No. 2005-100936, a discharge electrode is fixed to an electrode fixing plate of a sheet metal member, and the sheet metal member is fixed to a counter electrode by using a fixing insulator. Specifically, the sheet metal member and the fixing insulator configure an integral supporting member, and this supporting member supports the discharge electrode and the counter electrode.
When such a device as an air conditioner, an air cleaner, or the like is operated to use a discharge unit, conductive contaminants such as tobacco stains included in room air, ammonium nitrate generated by discharging, and the like adhere to a supporting member. In a structure where a discharge electrode and a counter electrode are supported by an integral supporting member, when more contaminants adhere to the supporting member, insulating properties between the discharge electrode and the counter electrode might be deteriorated. Then, when further more contaminants are adhered to cause the discharge electrode to connect to the counter electrode, the discharge electrode and the counter electrode conduct with each other to prevent discharging.